capo-cloudformation: typed, async Python SDK for AWS Cloudformation¶

capo-cloudformation is a typed Python SDK for AWS Cloudformation. It has an async client, AsyncCloudFormationClient, for asyncio and trio, and a sync client, CloudFormationClient, with the same methods. Requests and responses are typed with TypedDicts, so your editor and type checker know every field.

It is part of capo, a community-driven alternative to boto3 and aioboto3, built on its own HTTP stack instead of botocore and generated from the official AWS Smithy models. Documentation: https://capo-sdk.dev/services/cloudformation/

Installation¶

pip install capo-cloudformation

Usage¶

from capo_cloudformation import AsyncCloudFormationClient


async def main():
    async with AsyncCloudFormationClient() as cloud_formation:
        # Example: call the activate_organizations_access operation
        response = await cloud_formation.activate_organizations_access()
        print(response)

Pagination¶

Some operations in this SDK support pagination. If the operation supports pagination it will have an iter_ prefixed method that returns an async iterator.

from capo_cloudformation import AsyncCloudFormationClient


async def main():
    async with AsyncCloudFormationClient() as cloud_formation:
        # Example: paginate over describe_account_limits
        async for item in cloud_formation.iter_describe_account_limits():
            print(item)

Waiters¶

Waiters poll an operation until a resource reaches a desired state. If the operation supports waiters it will have a wait_until_ prefixed method.

from capo_cloudformation import AsyncCloudFormationClient


async def main():
    async with AsyncCloudFormationClient() as cloud_formation:
        # Example: wait for stack_exists
        await cloud_formation.wait_until_stack_exists(max_wait_time=300)

Error Handling¶

The SDK raises exceptions for errors returned by the API. Catch them to handle failures gracefully.

from capo_cloudformation import AsyncCloudFormationClient
from capo_cloudformation.error import InvalidOperationException


async def main():
    async with AsyncCloudFormationClient() as cloud_formation:
        try:
            await cloud_formation.activate_organizations_access()
        except InvalidOperationException as e:
            print(f"Error: {e}")
            print(e.data)  # additional error data

Retrying¶

The SDK retries failed operations automatically. Retry behaviour follows the Smithy specification: errors are retried based on their is_retryable and is_throttling_error attributes. Throttling errors use a longer base delay. Network-level failures (connection errors and timeouts) are also retried. Non-retryable errors, such as client errors without the @retryable trait, are raised immediately without further attempts.

The number of attempts defaults to 3 and can be changed at the client level via retry_max_attempts, or per call via config_overrides.

from capo_cloudformation import AsyncCloudFormationClient


async def main():
    async with AsyncCloudFormationClient() as cloud_formation:
        # Default: 3 attempts for every operation
        response = await cloud_formation.activate_organizations_access()

        # Override per operation
        response = await cloud_formation.activate_organizations_access(config_overrides={"retry_max_attempts": 5})

        # Disable retries for this call
        response = await cloud_formation.activate_organizations_access(config_overrides={"retry_max_attempts": 1})